The present invention relates to the technical field of apparatuses for applying paint on basically flat parts, known on the market as paint spray booths. In particular, the present invention relates to the shape of their plenum, wherein plenum means a ceiling able to distribute an airflow entering into a space.
Spray booths are known that apply spray paint through automatic devices (reciprocators, rotating spraying system, carousel-rotating system, gantry-robots, anthropomorphic robots) on parts to be painted.
Spray paint application entails that not all the paint hits the part to be painted; the paint not hitting flat parts partly hits the conveying system, and partly hovers in the air in the spray booth itself. This last portion of sprayed paint is called overspray, and is partially intercepted by spray booth suction system.
Non-intercepted overspray tends to contaminate spray booth internal walls, gathering on them up to the point of compromising manufacturing quality and leading to an important waste of painted parts. Therefore costly maintenance and cleaning of the spray booth itself become mandatory.
The overspray intercepted by the suction system is channeled towards spray booth filters, thanks to an air flow produced by the suction system itself, too. In this path the overspray is controlled in a more proper way thanks to the emission of an air flow from the plenum.
Examples of the prior art are U.S. Pat. No. 5,153,034 and US 2003/0183166 describing a paint spray booth having a sloping dual plenum, formed by two sloping plenums moving independently.
Another shape known in the prior art is a flat plenum, horizontal and parallel to the part to be painted, as disclosed in WO 0185357.